/**
 * Copyright (c) 2018, University Osnabrück
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the University Osnabrück nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL University Osnabrück BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <algorithm>

#include "lvr2/util/Util.hpp"

namespace lvr2
{

int Util::getSpectralChannel(int wavelength, PointBufferPtr p, int fallback)
{
    UCharChannelOptional spectral_channels = p->getUCharChannel("spectral_channels");
    if (!spectral_channels)
    {
        return fallback;
    }

    int minWavelength = *p->getIntAtomic("spectral_wavelength_min");

    int channel = (wavelength - minWavelength) / wavelengthPerChannel(p);

    if (channel < 0 || channel >= spectral_channels->width())
    {
        return fallback;
    }

    return channel;
}

int Util::getSpectralWavelength(int channel, PointBufferPtr p, int fallback)
{
    UCharChannelOptional spectral_channels = p->getUCharChannel("spectral_channels");
    if (!spectral_channels)
    {
        return fallback;
    }
    
    int minWavelength = *p->getIntAtomic("spectral_wavelength_min");

    if (channel < 0 || channel >= spectral_channels->width())
    {
        return fallback;
    }

    return channel * wavelengthPerChannel(p) + minWavelength;
}

float Util::wavelengthPerChannel(PointBufferPtr p)
{
    UCharChannelOptional spectral_channels = p->getUCharChannel("spectral_channels");
    if (!spectral_channels)
    {
        return -1.0f;
    }

    int minWavelength = *p->getIntAtomic("spectral_wavelength_min");
    int maxWavelength = *p->getIntAtomic("spectral_wavelength_max");

    return (maxWavelength - minWavelength) / static_cast<float>(spectral_channels->width());
}

} // namespace lvr2
